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Biotechnological uses of Azotobacter vinelandii:
Current state, limits and prospects
A. Díaz-Barrera* and E. Soto
Escuela de Ingeniería Bioquímica, Pontificia Universidad
Católica de Valparaíso, Chile,
Av. Brasil 2147, Casilla 4059, Valparaíso, Chile.
*Corresponding author. E-mail:
alvaro.diaz@ucv.cl. Fax: (56-32) 2273803.
Abbreviations:
PHB, poly-b-hydroxybutyrate;
DOT, dissolved oxygen tension; OTR, oxygen
transfer rate.
Accepted 23 March, 2010 |
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Azotobacter vinelandii
is a bacterium obligate aerobe able to fix nitrogen and grow
under microaerophilic conditions. This microorganism has
remarkable cellular machinery with the ability to
biosynthesize three molecules of important biotechnological
and biomedical applications: the extracellular
polysaccharide alginate, the intracellular polyester poly-b-hydroxybutyrate
(PHB) and siderophores compounds. Alginate and PHB have been
produced in shake flasks and bioreactors (at laboratory
scale) under different environmental and nutritional
conditions. This mini-review gives a current overview on the
application of wild-type and mutant’s strains of A.
vinelandii in bioprocesses to produce alginate or PHB.
Scales of production implemented and fermentation strategies
used as well as the potential limitations of the use of
A. vinelandii cells are analyzed. Based on an approach
that integrates molecular and bioengineering techniques, new
experimental strategies to enhance the productivity of
alginate and PHB from A. vinelandii are proposed.
Key words:
Azotobacter vinelandii, alginate, poly-b-hydroxybutyrate,
siderophores, bioprocess, scales of production. |
